FeBTC as peroxidase mimic for colorimetric cholesterol detection

Cholesterol sensing is essential for the early detection of several diseases such as hypercholesterolemia, atherosclerosis, and cardiovascular disorders. To address the limitations of enzyme-based methods, this paper proposes a novel Metal Organic Framework (MOF)-based spectrophotometric platform for cholesterol detection. Iron-based MOF (Fe-BTC) is introduced as a novel, peroxidase mimic nanozyme for cholesterol detection. Characterization studies run on Fe-BTC, including Fourier transform infrared spectroscopy, X-ray diffraction, and zeta potential, revealed its stable, amorphous nature and potential peroxidase activity due to Fe centers. Parametric studies including pH, time, temperature, and reagent concentrations were performed to determine operating conditions for H2O2 and cholesterol detection. Mechanistic studies demonstrated biosensor operation via OH· radical formation by Fe-BTC. The present biosensor achieved a cholesterol limit of detection (LOD) of 2.91 µM and 2.88 µM at 25 °C and 37 °C cholesterol incubation, respectively, with a linear detection range of 6.56–78.75 µM at both temperatures. The biosensor had good selectivity to cholesterol in the presence of interfering analytes, including glycine, uric acid, glucose, and NaCl. Overall, our novel Fe-BTC-based biosensor demonstrated comparable performance to nanomaterial-based cholesterol sensors reported in the literature, with a simpler, cheaper, and scalable design, and shows great promise for cholesterol detection via spectrophotometric methods.